1. Technical Field
This invention relates generally to heavy-duty flat wiper blade assemblies.
2. Related Art
Heavy-duty flat wiper blade assemblies are known having a straight body mounting a rubber wiper element. In one known construction, the body is extruded from a plastic which is, in turn, reinforced by a metal stiffener to provide sufficient structural rigidity to the body, as shown in U.S. Pat. No. 3,107,384. In another known construction, the body is fabricated from a strip of steel which is bent into a generally U-shaped profile in cross-section and crimped along its length to the rubber wiper element to secure the wiper element. In this case, the flat steel body component is cut to length along with the wiper element prior to folding the flat steel over the wiper element.
Both such constructions are costly to manufacture and are limited in the features and advantages they can offer.
Heavy-duty flat wiper blade assemblies constructed according to the present invention overcome or greatly minimize the foregoing limitations of prior wiper blade assemblies.
A heavy-duty flat wiper blade assembly has a wiper element and an extruded metallic frame. The frame has a bottom channel with a slot and an upper channel separate from the bottom channel. The wiper element is disposed in the bottom channel and extends through the slot to make contact with a surface to be wiped. The upper channel is closed and may optionally be provided with a fluid inlet opening for receiving wiper fluid into the channel and a fluid outlet opening for discharging the wiper fluid from the upper channel and onto a surface to be wiped.
Additionally, a method for manufacturing a wiper blade is provided wherein a wiper element is slidably inserted into a bottom channel of an extruded metallic frame. The wiper element depends from the bottom channel and through a slot in the bottom channel to make wiping contact with a surface to be wiped. A wall of the bottom channel is then staked to fix the wiper element within the bottom channel. An optional method eliminates the staking step and installs a pair of end plugs into each end of the frame to releasably maintain the wiper element within the bottom channel.
Some advantages of the invention include providing for increased efficiencies in the manufacture and assembly of a heavy-duty wiper blade assembly by reducing the number of operations required to produce the wiper blade assembly, by reducing the scrap, by improving the handling of the wiper blade components during assembly and by reducing the time required for assembly, thus reducing the total costs of producing the wiper blade assembly.
Another advantage of the invention is the ability to utilize the closed upper channel as a passage for conveying wiper fluid from which the fluid may be dispensed directly on the surface to be wiped.
Another advantage of the invention is a reduction in the amount of material used in the wiper element.